gallup<-read.csv("/Users/moch/Dropbox/SMOKING/gallup2.csv")
okay <- !is.na(gallup$lung)
okay2 <- !is.na(gallup$throat)
okay3 <- !is.na(gallup$disease)

plot(which(okay),gallup$lung[okay],type="o",pch=21,lty=2, xaxt="n",ylim=c(0,85),col="grey85",xlab="Year",ylab="Percent")
axis(1, at=c(1,11,21,31,41,51),lab = c("1950","1960","1970","1980","1990","2000"))
lines(which(okay2),gallup$throat[okay2],col="grey45",type="o",pch=22,lty=3)
lines(which(okay3),gallup$disease[okay3],col="black",type="o",pch=23,lty=4)
legend(5,85, c("Lung Cancer","Throat Cancer", "Heart Disease"), cex=0.8, 
       col=c("grey85","grey45","black"), pch=21:25, lty=2:9)


 